Classification schemes have been developed for individual components
of the reinforcing materials system and include primers, adhesives, laminating
resins, fibre pre-forms and pre-formed FRP composites. An example can be found
here.

The future intention is to include material systems classified
for loading types other than flexure (e.g. compression, shear, fatigue and
impact) as, and when, suitable test methods become available. There is scope,
however, within the given schemes to include extreme environmental conditions
in certain applications.

The main focus of the classification methodology is not to be
prescriptive, by setting minimum performance requirements, because most design
solutions are unique. Thus short-term values are determined from current standard
test methods, from which characteristic values for design and acceptance values
for on-site QC testing can be derived. An interactive document explaining
requirements of the classification testing can be found here.

Classification of adhesive materials

Three fundamental aspects for the successful application of
adhesive materials used for strengthening purposes include:

The working characteristics of an adhesive are critical
to successful on-site application, and include storage life, usable life and
curing requirements. The mechanical properties of the adhesive, or resin,
currently form part of the design requirement and their importance is self-evident.
The test methods for defining the performance requirements for the classification
of adhesives and resins for flexural strengthening are given below:

The short term testing requirements for working characteristics
and cured bulk properties are given here:

The third aspect, adhesion, represents the least well understood
of the requirements and yet is crucial for ensuring bond integrity and long-term
durability. Testing requirements for adhesion and durability are given here:

Classification of composite materials

Composite materials may be considered either as a prefabricated
component or as an in situ site-laminated plate. Prefabricated components
may include standard forms such as pultruded rods, bars, beams and plates,
or, bespoke beams, shells and profiles. Externally bonded or near-surface
mounted reinforcement for flexural strengthening typically involves pultruded
plates, or rods, that can be used either in an unstressed or prestressed state.

The Classification Scheme for composite materials has been devised
for applications involving flexural strengthening. The performance requirements
and test methods associated with two separate aspects are then considered:

Adhesion to the composite materials is assessed under
the adhesive, or resin, classification. The test methods for defining the
performance requirements for the classification of composite reinforcement
for flexural strengthening are given below:

Classification documentation

An example of the completed classification scheme for
a structural epoxy adhesive system used for a flexural plate bonding application
is shown below. The various elements of the scheme and how they should be
interpreted are accessed by scrolling over different parts of the table (this
feature is currently still under development). A blank template can be downloaded
for your own use here.

A printer-friendly version of the following example is
available from here.

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Services. This page last updated: Sept 19th, 2011